The RB4000 junction boxes, suitable for installation in wood and raised access modular floors are the perfect solution for data centers, commercial office buildings and places where underfloor wiring distribution is required.The FBS Junction boxes are an excellent solution to join different runs or change the direction of the conduits or cables and provide space for the connection and branching of the enclosed conductors. The RB4000 junction boxes are supplied with 18 concentric knockout's for 1/2 and 3/4'' conduits.FBS Junction Boxes are designed for use with the PMC47 floor boxes.